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author | Huacai Chen <chenhuacai@loongson.cn> | 2022-05-31 18:04:11 +0800 |
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committer | Huacai Chen <chenhuacai@loongson.cn> | 2022-06-03 20:09:28 +0800 |
commit | 559671e04a33b183b6e65fd585ab2e2a0578208b (patch) | |
tree | 1fe8b2bf52ca14bad194049ff85d662f3b3b2e81 /arch/loongarch/lib/delay.c | |
parent | 7153c3cbb5b9b99755659b97861fd4fc909ed86f (diff) | |
download | linux-stable-559671e04a33b183b6e65fd585ab2e2a0578208b.tar.gz linux-stable-559671e04a33b183b6e65fd585ab2e2a0578208b.tar.bz2 linux-stable-559671e04a33b183b6e65fd585ab2e2a0578208b.zip |
LoongArch: Add some library functions
Add some library functions for LoongArch, including: delay, memset,
memcpy, memmove, copy_user, strncpy_user, strnlen_user and tlb dump
functions.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/lib/delay.c')
-rw-r--r-- | arch/loongarch/lib/delay.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/loongarch/lib/delay.c b/arch/loongarch/lib/delay.c new file mode 100644 index 000000000000..5d856694fcfe --- /dev/null +++ b/arch/loongarch/lib/delay.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020-2022 Loongson Technology Corporation Limited + */ +#include <linux/delay.h> +#include <linux/export.h> +#include <linux/smp.h> +#include <linux/timex.h> + +#include <asm/compiler.h> +#include <asm/processor.h> + +void __delay(unsigned long cycles) +{ + u64 t0 = get_cycles(); + + while ((unsigned long)(get_cycles() - t0) < cycles) + cpu_relax(); +} +EXPORT_SYMBOL(__delay); + +/* + * Division by multiplication: you don't have to worry about + * loss of precision. + * + * Use only for very small delays ( < 1 msec). Should probably use a + * lookup table, really, as the multiplications take much too long with + * short delays. This is a "reasonable" implementation, though (and the + * first constant multiplications gets optimized away if the delay is + * a constant) + */ + +void __udelay(unsigned long us) +{ + __delay((us * 0x000010c7ull * HZ * lpj_fine) >> 32); +} +EXPORT_SYMBOL(__udelay); + +void __ndelay(unsigned long ns) +{ + __delay((ns * 0x00000005ull * HZ * lpj_fine) >> 32); +} +EXPORT_SYMBOL(__ndelay); |